000
AXPZ20 KNHC 042220
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN MAR 04 2012
 
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2115 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

ITCZ FROM 04N88W TO 00N100W...AND FROM 01N111W TO 02N115W TO 
00N129W. SCATTERED MODERATE ISOLATED STRONG S OF 03N BETWEEN 98W 
AND 102W.

...DISCUSSION...

MIDDLE TO UPPER LEVEL ANTICYCLONIC FLOW PREVAILS ACROSS THE AREA 
EAST OF 125W...AS RIDGING ALONG 100W YESTERDAY HAS SHIFTED WWD 
ACROSS MEXICO AND INTO THE EPAC IN ADVANCE OF A SHORTWAVE TROUGH 
CURRENTLY EXTENDING FROM 32N132W TO 20N127W. AT LOWER 
LEVELS...THE EPAC HIGH PRES RIDGE CONTINUES ANCHORED TO A 
WEAKENING 1027 MB HIGH NEAR 40N130W EXTENDING SE TO N PORTIONS 
OF BAJA CALIFORNIA...AND CONTINUES TO INDUCE STRONG NWLY WIND 
FLOW THROUGH THE ENTIRE LENGTH OF THE GULF OF CALIFORNIA...WHERE 
SEAS TO 9 FT ARE EXPECTED S OF 26N. FRESH TRADEWINDS ARE FOUND S 
OF THE HIGH...ROUGHLY FROM 06N TO 15N WEST OF 126W...AND WILL 
DIMINISH IN INTENSITY AND AREAL EXTENT AS THE SURFACE HIGH 
WEAKENS AND SHIFTS SOUTHWARD. THE RIDGE WILL RE-BUILD BY THE 
MIDDLE OF THE WEEK AS THE DEEP LAYER RIDGE BECOMES 
RE-ESTABLISHED IN THE NORTHWESTERN PACIFIC OCEAN ALONG 140W. 
THIS IN TURN WILL FRESHEN THE TRADEWIND FLOW FROM 05N TO 20N W 
OF 110W BY WEDNESDAY. A BROAD AREA OF NORTHWESTERLY SWELL MIXING 
WITH FRESHER NORTHEASTERLY TRADEWIND SWELL WILL DECAY GRADUALLY 
THROUGH WEDNESDAY.

GAP WINDS...

GULF OF CALIFORNIA...THE PRES GRADIENT BETWEEN THE HIGH OFFSHORE 
OF NORTHERN CALIFORNIA AND LOWER PRESSURE ALONG THE SIERRA MADRE 
OCCIDENTALES OF W MEXICO CONTINUES TO YIELD STRONG NWLY FLOW 
THROUGH THE BASIN. THESE WINDS ARE EXPECTED TO DIMINISH BELOW 20 
KT BY MON MORNING AS THE PRES GRADIENT LOOSENS BETWEEN THESE 
WEAKENING FEATURES.

GULF OF TEHUANTEPEC...A COOL AIR MASS BEHIND A GULF OF MEXICO 
COLD FRONT IS PUSHING STRONG GAP WIND FLOW THROUGH THE CHIVELA 
PASS TODAY...THEN THROUGH AND DOWNSTREAM OF THE GULF OF 
TEHUANTEPEC. NO MARINE OBSERVATIONS HAVE BEEN RECEIVED TO 
CORROBORATE MODEL FORECASTS...AND IT IS ASSUMED THAT A SMALL 
AREA OF MAX WINDS 45-50 KT CONTINUE THROUGH THIS GULF THIS 
AFTERNOON...WITH A LARGE AREA OF GALES EXTENDING WELL 
DOWNSTREAM...WITH SEAS AS HIGH AS 18-19 FT. A LONG PLUME OF 
WINDS OF 20 TO 30 KT WILL CONTINUE TO EXTEND FARTHER SOUTH AND 
SOUTHWESTWARD...REACHING AS FAR AS 10N100W BY TUESDAY. 
NORTHEASTERLY SWELL WILL BUILD IN THIS PLUME...MIXING WITH 
LONGER PERIOD NORTHWESTERLY SWELL THROUGH THE MIDDLE OF THE 
WEEK. THE WINDS WILL DIMINISH TO STRONG GALES MONDAY 
MORNING...AND THEN TO LESS THAN GALE FORCE ON WEDNESDAY EVENING. 

GULF OF PAPAGAYO...THE WIND SPEEDS THROUGH THE GULF OF PAPAGAYO 
WILL INCREASE QUICKLY TO 20 TO 25 KT TONIGHT...AND THEN FROM 20 
TO 30 KT BY MONDAY MORNING. THESE WINDS WILL SPREAD 
SOUTHWESTWARD AND DOWNWIND OF THE GULF BEYOND 300 NM BY MIDDAY 
MONDAY...WITH SEAS BUILDING TO 12 FT. THIS WILL OCCUR AS THE 
PRESSURE GRADIENT BEHIND THE GULF OF MEXICO COLD FRONT 
EVENTUALLY EXPANDS ACROSS CENTRAL AMERICA TONIGHT AND MONDAY.  

$$
STRIPLING